Surely; certainly — used to indicate that something is true or to agree/emphasize a point.
確かに彼の言うことには一理ある。
Indeed, there's some truth to what he says.
昨日は確かに雨が降っていたと覚えている。
I remember that it was definitely raining yesterday.
確かに、その方法なら時間を節約できるだろう。
Certainly, that method would probably save time.
彼女は確かに来ると言っていたが、まだ到着していない。
She did say she'd come, but she hasn't arrived yet.